1. Field of the Invention
The present invention relates to the field of performance enhancing shoe components or inserts for use in conjunction with various types of foot-ware. More particularly, the present invention relates to the field of performance enhancing shoe components or inserts which absorb and store energy of local loads and forces, through elastic deformation, and then return the energy to the shoe wearer, or to an object struck by a shoe, in useful form as the load is removed.
2. General Background of the Invention
There is a high demand for athletic equipment which enhances the performance of athletes. At all levels of athletic competition, small improvements in performance can be the difference between success and failure. At the highest levels of athletics, the difference of a few tenths or hundredths of a second is all that separates the elite athlete from the ordinary. For this reason, equipment which improves performance even slightly, will be desired in high demand. The newer materials used in tennis racket construction or golf club shafts are examples of equipment which improves performance by absorbing and storing energy, then returns this energy in a useful form as the load is removed.
This high demand for performance enhancing athletic equipment includes the art of athletic shoes and shoe components. Most recent improvements in athletic shoes or athletic shoe components have been made for aesthetic reasons or for comfort or to reduce weight. Few changes in athletic shoes or their components have been for meaningful increases in athletic performance. Present athletic shoes and their components fail to provide an energy return to the wearer. Neither do they absorb energy and return energy to a ball or object struck by the shoe. Description of Prior Art
Athletic shoes typically comprise a fabric, leather or synthetic upper, an outsole including a treaded or cleated lower surface, and a midsole positioned between the outsole and the foot of the wearer. There may also be an insole positioned between the outsole and the foot of the wearer. If the shoe is not manufactured with an insole, a wearer may add an insole or replace the midsole with an insole.
The midsole of a conventional athletic shoe is generally formed from a flexible, resilient, relatively soft material in order to absorb shock that results from impact of the shoe with the ground. A typical outsole is made of a higher density, tougher, more rigid material in order to protect the shoe from degradation and to support the foot. The outsole must also be flexible in order to facilitate ease of movement of the foot during certain athletic motions.
The following US patents are incorporated herein by reference:    U.S. Pat. Nos. 4,454,662, 4,506,460, 4,858,338 5,025,573 5,052,130 5,179,791 5,203,793, 5,452,526, 5,572,804, 5,695,850 5,960,566, 6,120,880, 6,145,221 6,205,683, 6,485,661.    U.S. Pat. No. 5,572,804 discloses an inner sole for an athletic shoe that can have many degrees of stiffness, by the application of multiple inserts into the sole.    U.S. Pat. No. 5,452,526 discloses a soccer shoe with an outsole stiffener; the stiffening inserts are molded into the outer sole.    U.S. Pat. Nos. 6,120,880 and 5,694,850 disclose placing inserts into various portions of the insole of an athletic shoe to enhance performance.    U.S. Pat. No. 6,205,683 discloses placing a torsional insert within the inner sole of an athletic shoe.    U.S. Pat. No. 4,454,662 of 1984 issued to Stubblefield adds stiffening components to the arch and heel portions of the shoe. The present invention adds flexible components to just the front or to the front and outside edges of the shoe. The present invention may provide some measure of arch support, but little or no heel support. The shoe/sole/insert of an embodiment of the present invention will have a shape, location and function significantly different than the stiffening components in this patent.
There are numerous articles of footwear in the prior art in which inserts and shoe components are present in order to provide comfort, stability or support for the foot. For example, U.S. Pat. No. 4,506,460 of 1985 issued to Rudy describes moderators and stabilizers located under the forefoot and heel. The purpose of these moderators and stabilizers is to cushion shock forces, provide improved support, control and stability, store energy and return energy to the wearer. These moderators and stabilizers are located under and vertically alongside the forefoot and heel of the wearer. The present invention's primary location will be the toe of the shoe with little or nothing supporting the heel and forefoot. The shoe/sole/insert of embodiments of the present invention preferably have both horizontal and vertical components, with the vertical component only at the toe end of the shoe. The horizontal component of the shoe/sole/insert of embodiments of the present invention can differ in shape and location within the shoe.    U.S. Pat. No. 5,452,526 of 1995 issued to Collins describes a two-part stiffener, the first portion of which stiffens the waist or shank of the outsole; and the second portion both stiffens and provides resiliency to the forepart of the outsole. The purpose of this two-part stiffener is to provide physical properties which are selected for the appropriate use of the shoe and to provide comfort to the wearer. These stiffeners operate to stiffen the shank or waist of the outsole and a fore part of the outsole in response to transverse flexure of the user's foot at the ball of the foot. These stiffeners are relatively complex in shape and located in various places throughout the outsole and arranged in a manner to resist flexure about the longitudinal axis of the shoe. The shoe/sole/insert of embodiments of the present invention preferably provide resilience primarily in response to vertical flexure of the user's foot at the toe, or even in front of the toe, and to a lesser extent, in response to some transverse flexure only at the outside edge of the foot. The shoe/sole/insert of embodiments of the present invention preferably have relatively simple shapes with a location farther forward and whose function is not lateral support, but a vertical return to its original shape.    U.S. Pat. No. 5,572,804 issued to Skaja et al. in 1996 details method of construction of shoe midsole components from a flexible high polymer resin. These shoe sole components are formed from two sheets of thermoplastic resin, with each sheet consisting of different materials having different properties and containing varying shapes and sizes of support members. These support members comprise inwardly directed indentations in each sheet of the thermoplastic resin which must be precisely aligned with the matching indentation. The shoe/sole/insert of embodiments of the present invention will not be restricted to only the midsole, nor will it consist of a plurality of shaped protrusions scattered throughout the midsole component material. The horizontal component of the present invention can preferably be a thin, flat or slightly curved object consisting of a single or very few individual sizes and shapes extending to the front and side edges of the shoe outsole or midsole or inserted insole. Only if the present invention is hollow will it be important to more precisely match various protrusions or indentations.    U.S. Pat. No. 5,695,850 issued to Crow in 1997 is a performance shoe component consisting of 1,4-polybutadiene and a natural or synthetic rubber. This shoe component is most advantageously placed beneath the ball of the foot. The purpose of that location is to improve the wearer's ability to leap higher or run faster or provide cushioning. The horizontal component of the shoe/sole/insert of embodiments of the present invention will be most advantageously placed under and possibly beyond the front edges and outside edges of the shoe. The vertical component of the shoe/sole/insert of embodiments of the present invention are preferably most advantageously placed on top of, or directly above, the horizontal component. This location is intended to maximize the absorption of energy and to return a portion of this energy to the object struck.    U.S. Pat. No. 5,960,566 issued to Brown in 1999 and U.S. Pat. No. 6,485,661 issued to Brown in 2002 both consist of a composite material orthotic insert configured to enhance control over the motions of the foot within the shoe. The stated purpose of the insert is to control the movements of certain joints of the foot during walking and running. This orthotic insert is positioned under the heel and forefoot. The shape and position of the insert and its purpose in the aforementioned patent is clearly distinguishable from the shoe/sole/insert of embodiments of the present invention.    U.S. Pat. No. 6,120,880 issued to Crow in 2000 is a continuation of U.S. Pat. No. 5,695,850. The characteristics which distinguish the present invention from this patent are the same as those outlined above.    U.S. Pat. No. 6,205,683 issued to Clark et al. in 2001 is for an insole board which includes a shock diffusion plate located under the heel and midfoot. The location, shape and purpose of the shoe/sole/insert of embodiments of the present invention are clearly distinguishable.    U.S. Pat. No. 4,858,338 discloses an insert for a shoe sole, which includes an elastic strip, which absorbs and stores the energy of running and returns the energy to the wearer.    U.S. Pat. Nos. 5,025,573 and 5,179,791 disclose a composite shoe bottom with layers of firm and softer materials, which provide firm support and lateral stability.    U.S. Pat. No. 5,052,130 discloses a spring plate made of multiple layers of carbon fiber embedded in a polymer which stores and releases energy in a manner beneficial to a runner.    U.S. Pat. No. 6,145,221 discloses a cleated athletic shoe incorporating a cleat frame which supports the cleats in a manner which transfers upward forces from the cleat into the cleat frame when the shoe is weighted.    U.S. Pat. No. 5,720,118 issued to Mayer in 1998 provides an inlay for a shoe. The inlay comprises one piece of a hard material, preferably selected from metal, plastic, steel and spring steel. The stated purpose of this inlay is to reduce the risk of lateral snapping over of the foot, thus reducing the risk of ligament tears and strains. Another stated purpose is to protect the bottom of the foot from right angle pressures by distributing over the entire inlay pressures caused by small stones or uneven ground. This patent further describes a toe cap riveted to the inlay. This cap is made of spring steel; its stated function is to protect the toes and forefoot from falling objects.
The preferred embodiment of the present invention also consists of a horizontal and vertical component. An embodiment of the present invention has the vertical component forming a toe cap. Although the horizontal component may be made of metal, plastic or steel, the vertical component should be made of a softer, more energy absorbent material. The purpose of the vertical component in the present invention is not to protect the toes and forefoot from falling objects; rather, it is to transmit energy to the horizontal component so that both components working together will return more energy to the object struck by the wearer. The vertical component need not be riveted or otherwise attached to the horizontal component. It can fulfill its function merely by being placed directly above the horizontal component.
There are numerous articles of footware in the prior art in which inserts and shoe components are present in order to provide comfort, stability or support for the foot. The purpose of these moderators, stabilizers and orthotics is to cushion shock forces, provide improved support, control and stability, store energy and return energy to the wearer. An essential difference between the prior art and the preferred embodiments of the present invention is the vertical component. The vertical component is preferably located at the toe end of the shoe, and it will preferably rest upon the horizontal component, or be located directly above the horizontal component. The vertical component may be permanently attached to the horizontal component, or it may be manufactured as a separate piece and later attached to the horizontal component or placed above the horizontal component. The vertical component may be used without the horizontal component, it may be used as an insert resting upon or located above the midsoles and/or outsoles of the prior art. The prior art primarily serves to provide comfort and stability to the wearer, or to increase the return of energy to the wearer. The primary purpose of embodiments of the present invention is to increase the return of energy to the object struck by the wearer.
The shoe/sole/insert of embodiments of the present invention preferably provide resilience primarily in response to vertical flexure at the toe, or in front of the toes of the foot of the wearer. To a lesser extent there may also be resilience in response to vertical flexure at the inside and outside edges of the forefoot. The shoe/sole/insert of embodiments of the present invention may have relatively simple shapes. The horizontal component can preferably be thin and flat or slightly curved objects consisting of individual sizes and shapes extending to the front and side edges of the shoe outsole or midsole or inserted insole.
A primary characteristic of the shoe/sole/insert of embodiments of the present invention, which distinguishes the present invention from most other patents incorporated by reference, is that of the vertical component. This vertical component preferably rests upon the horizontal component, or if not directly upon the horizontal component, the vertical component is located above the horizontal component. In order to increase the elastic deformation of the horizontal component of the shoe/sole/insert of embodiments of the present invention, in certain types of kicks or other uses of the shoe, the vertical component will be the first portion of the shoe/sole/insert to make contact with the object struck. In making contact with the object, this vertical component will absorb and transfer more energy to the horizontal component of embodiments of the present invention, which would return more energy to the object struck by the shoe, than would be possible without the vertical component. If the vertical component is not present, the foot inside of the shoe would make contact with the object struck before the horizontal component could make contact. The foot in such case would absorb some portion of the energy created in striking the object and could only transfer the unabsorbed energy to the horizontal component of embodiments of the present invention. The less energy transferred to the horizontal component, the less the horizontal component can be flexed, and the less the horizontal component is flexed, the less energy the horizontal component can transfer to the object struck, or to the wearer of the shoe.
The vertical component of the shoe/sole/insert of embodiments of the present invention will produce a more efficient transfer of the energy produced by the physical act of striking the object, back to the object struck. When a foot inside of a shoe without the shoe/sole/insert of embodiments of the present invention makes contact with the object struck, the foot acts as a type of energy sponge situated between the object struck and the horizontal component of embodiments of the present invention. The energy absorbed by the foot will be transferred to the bones, ligaments, tendons and muscles of the foot and leg. This absorbed energy will be felt in the foot and leg as heat. The more heat absorbed by the bones, ligaments, tendons and muscles of the foot and leg, the more fatigue and discomfort will be felt by the wearer of the shoe.